This application claims benefit of Japanese Patent Application No. 2002-192580 filed on Jul. 1, 2002, the contents of which are incorporated by the reference.
The present invention relates to data terminal devices for displaying road map based on position data transmitted from an artificial satellite.
Portable telephone set is well known in the art, which can display a map on a display unit such as a liquid display panel.
In the prior art portable telephone set, however, such map is displayed on the entire screen of the display unit. This means that even data in an unnecessary range is displayed, thus making it difficult to recognize necessary data. Also, in the prior art portable telephone set, the sole road map is displayed, no data for walking people, such as crossroads and walking road bridges, is displayed. This means that when it is desired to guide a walking person with a map such as the car navigation, it has been impossible to adequately guide the walking person because of no display of data for walking people such as crossroads and walking road bridges.